After 16 weeks on the Washington Redskins’ practice squad, rookie wide receiver Aldrick Robinson figured he wouldn’t get a call-up to the team’s 53-man roster.

So when the Southern Methodist University product got the call from his agent Tuesday and learned that the Redskins, who drafted him in the seventh round last April, were promoting him, Robinson was surprised.

“It’s a good late Christmas gift to get on the roster and be part of the team,” said the 5-foot-10, 178-pound Robinson, who had a prolific career at SMU with 81 catches for 3,314 yards and 30 touchdowns. “I feel like it’s been a long time. But it’s over now. To be part of the 53 feels good.”

Part of a crowded receiver unit during training camp, Robinson struggled to distinguish himself. He didn’t record a catch, and he fumbled the two punts he tried to return.

Robinson becomes the ninth receiver on the roster, but says that if he gets the opportunity to play Sunday, his goal is simple.

“]To show] that I can play. That’s what I didn’t show in the preseason, and if I get the chance, that’s what I want to show,” Robinson said. “My route running, catching the ball [has improved]. Being consistent. I’ve also gotten better catching punts.”

The Redskins filled the practice squad spot previously held by Robinson Wednesday by signing running back Stafon Johnson, a free agent out of USC.

Johnson dislocated his ankle during a preseason game with the Tennessee Titans in 2010 and missed all of his rookie season. The 5-foot-11, 222-pounder’s senior season at USC ended when he dropped a barbell on his throat in the university’s weight room, causing serious injuries.